- #1
tomelwood
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Homework Statement
Let {p_n}n>0 be the ordered sequence of primes. Show that there exists a unique element f in the ring R such that f(p_n) = p_n+1 for every n>0 and determine the family I_f of left inverses of f.
Homework Equations
The ring R is defined to be: The ring of all maps f:Q+-->Q+ such that f(rs)=f(r)f(s) for every r,s in Q+. Define the operations + and x in such a way that (f+g)(r) = f(r)g(r) and (f x g)(r) = f(g(r)) for every r in Q+. This is a non commutative unitary ring with zero divisors.
The Attempt at a Solution
Any pointers would be appreciated, as I cannot see how it is possible to map one prime to the next, given any prime, let alone find the unique f in the ring R that will do it.
Sorry that I haven't provided more, but I have literally been banging my head against a wall for ages on this question, without the faintest idea of where to start!